Atmospheric CO2 over the last 1000 years: A record from the WAIS Divide ice core

Entry ID:
brook_0739766

Summary

Abstract:
These data are a decadally resolved record of atmospheric CO2 concentration for the last 1000 years, obtained from the West Antarctic Ice Sheet (WAIS) Divide shallow ice core.

Purpose:
The most prominent feature of the pre-industrial period is a rapid ~7 ppm decrease of CO2 in a span of ~20-50 years at ~ 1600 A.D. This observation confirms the timing of an abrupt atmospheric CO2 decrease of ~10 ppm observed for that time period in the Law Dome ice core CO2 records, but the true magnitude of the decrease remains unclear. Atmospheric CO2 variations over the time period 1000-1800 ... A.D. are statistically correlated with northern hemispheric climate and tropical Indo-Pacific sea surface temperature. However, the exact relationship between CO2 and climate remains elusive due to regional climate variations and/or uneven geographical data density of paleoclimate records. We observe small differences of 0~2% (0~6 ppm) among the high-precision CO2 records from the Law Dome, EPICA Dronning Maud Land and WAIS Divide Antarctic ice cores. However, those records share common trends of CO2 change on centennial to multi-centennial time scales, and clearly show that atmospheric CO2 has been increasing above preindustrial levels since ~ 1850 A.D.

Description:
The U.S research community is conducting a deep ice coring project in West Antarctica for studies of climate, ice sheet history and cryobiology. This project is collecting a deep ice core from the West Antarctic Ice Sheet (WAIS) ice flow divide and integrating approximately 20 separate but synergistic projects to analyze the ice and interpret the records